Powdered chemical reagents are widely employed in the photometric testing of water for constituent chemicals such as chlorine. Conventionally, a precisely predetermined amount of reagent is added to a test sample of water so that it turns a certain hue, which depends upon the concentration of the constituent element in question. This sample is then tested by a photometer, such as in the manner described by my prior U.S. Pat. No. 5,083,036, to determine the concentration of the constituent element in the test sample.
Using a correct amount of reagent is critical to the effectiveness of these photometric tests. Therefore, a number of packaging schemes have been devised which allow the tester to dispense an accurately premeasured dosage for each test. However, each of these has disadvantages. For example, each individual dosage of reagent may be supplied in a plastic vial having a flexibly attached cover. Although such containers are fairly convenient to use, they are also quite expensive. Alternatively, the premeasured dosages of reagent have been packaged in various types of foil packets and plastic "pillows". These containers are less expensive than vials. However, opening them and dispensing the reagent into the sample tends to be a relatively awkward and time consuming procedure. The tester usually must use both hands and often requires a cutting implement to open the package. All of these known products require the tester to store, monitor and handle numerous individual reagent containers.
Although various substance dispensers are known in other arts, none is optimally suited for use in dispensing reagents for photometric analysis. In particular, most conventional dispensers employ a rotary mechanism, which again requires that the tester employ both hands to dispense the substance. This increases the time and tedium associated with the testing, which can lead to mistakes and erroneous results.